[jf___]

A huge share of the gypsum used in drywall is *synthetic gypsum* — a byproduct of flue-gas desulfurization (FGD) at coal-fired power plants. When SO₂ is scrubbed from exhaust using limestone, the reaction produces calcium sulfate dihydrate, chemically identical to mined gypsum. In the US, FGD gypsum has accounted for roughly half of all gypsum consumed by the wallboard industry at its peak.

The "cheap, uniform, and free of defects" story is partly a story about coal. The drywall industry scaled on the back of an abundant, nearly free waste stream from the energy sector. It's a classic example of industrial symbiosis — one industry's pollution abatement becomes another's feedstock.

And it cuts the other way now: as coal plants shut down across Europe and North America, synthetic gypsum supply is shrinking. The drywall industry is facing a real raw material squeeze, with manufacturers having to shift back toward mined gypsum or find alternative sources. There's ongoing work on using phosphogypsum (from fertilizer production) but that comes with its own radioactivity concerns.

For someone in your position this is particularly relevant — the "wonder" of drywall is entangled with the fossil fuel economy in a way that makes earth-based construction methods look increasingly attractive as that supply chain unwinds.

[willis936]

This reminds me a bit of Hank Green's recent video on why we don't recycle plastic. The answer is we frack a lot of methane for electricity and ethane is a byporoduct of that. You can flare it off or use it as a negative cost ingredient for polyethane / many other plastics. As long as we're using lots of fossil fuels the byproducts will be cheap. Anyone who has played gregtech or factorio or similar already has an intuition for this. The answer then becomes simple: if you want less plastic you must use less fossil fuel. They are one and the same.

https://youtu.be/325HdQe4WM4

[glitchc]

Isn't that common knowledge, that plastics aren't feasible without fossil fuels?

[driscoll42]

I used to work for a drywall manufacturer who still owned their own mines despite efforts to divest from them by some. They always viewed it as a structural advantage to still own them and not be wholly dependent on the coal plants (which effectively have conveyor belts going from the coal plants to the wallboard plants). I imagine as time goes on it'll become even more of an advantage for them to still own those mines as their competitors are forced to buy at highly inflated prices (or even from them) as coal shuts down.

[trollbridge]

Or AI’s thirst for power will bring coal back.

[MisterTea]

> the "wonder" of drywall is entangled with the fossil fuel economy in a way that makes earth-based construction methods look increasingly attractive as that supply chain unwinds.

I keep thinking of that scene in Brazil where the hero, Harry Tuttle, opens a modular wall panel in Sam's apartment.

We standardized on 16 inch stud spacing here in the US a long time ago when we likely still used cement with a plaster skim coat on wood lath. Cutting up a board of nearly the same stuff feels primitive. You have to break open the wall to fix things.

To me the next logical step is a standard for modular walls that are laid out on a grid structure. I get that no one wants exposed screw holes but I can think of ways to hide them or make them part of a decorative pattern to blend them in. The coverings would be made to be cut to size as well. Wall panels would have to be environmentally friendly so wood is a first choice in natural and/or composite forms.

If you think this will look boxy then look up the passive house and notes on home building. Homes with a winding structure are difficult to seal reliably and roof so a boxy home is actually more economically friendly in terms of insulation to reduce HVAC energy consumption.

[bombcar]

We have exactly what you want - it's called shiplap or car siding.

It's wood that is nailed up in such a way that you can pretty easily remove and repair something and replace it.

However, inside wall things get done so rarely that the cost savings by using drywall more than covers paying someone to patch the drywall after a repair.

A middle ground is to run all utilities at the bottom or top of the wall, and use large baseboards/crown molding to cover it up.

[ragall]

> You have to break open the wall to fix things

The best is to build in such a way as to not have to fix them in the first place. European standards mandate passing all wiring through corrugated tubes. Builders add spare empty ones for future expansion, which makes it unnecessary to open the walls in most cases.

[intrasight]

> no one wants exposed screw holes

Wouldn't bother me. But I'm an engineer. But I think the holes can be plugged with removable plugs.

[dTal]

Interesting comment with worthwhile content, but the writing style strongly smells of ChatGPT, and the phrase "For someone in your position" is incongruous (who is being addressed?). Did you use it, and if so, would you mind sharing the prompt?

[some_random]

They're a founder of a startup doing this kind of thing, realistically they probably copied blurb per-prepared marketing blurb or something they sent to someone else.

[46493168]

“Terrestrial develops a robotic approach to earthen construction”. person you replied to claims to be a founder of this company, according to LinkedIn

Other “tells” in the comment are the subscript “2” and the full spelling of the chemical. Also 3 emdashes

[xnx]

Fascinating. I wonder if supply constraints will make drywall recycling profitable.

[PlunderBunny]

I don’t know about other countries, but in New Zealand there’s already recycling of leftover bits of drywall (we call it ‘gib board’ after a brand name). All the big building companies will accept leftover bits of gib board, but small bits can be thrown directly in your garden beds to help break up clay.

The gypsum used in New Zealand is mined locally.

[hettygreen]

Question: Would this process of creating synthethic gypsum leave any toxic chemicals from the scrubbing process at the coal power plant exhaust?